Plasmonicnanostructuresofferuniqueopportunities to assist chemicalreactionsthrougheitherphotocatalytic or thermalpathways. Ourresearchisfocused on couplingplasmonicnanoparticles and nanostructures to functionaloxideswhich are typicallyusedascatalysts to promotedifferentkind of reactions, like the photodegradation of environmentalpollutants and the production of energyvectors (e.g. H2) from renewablesources.

For example, wehaverecentlyfabricateddifferent model-systemsbased on TiO2 and ZnOphotocatalyticbeadscoupled to Aunanoantenna arrays. Thesesystemsallow for either broadband or selective, veryefficient light harvesting in the Vis-NIR range.
Light isconcentratedwithinnanogapregions, generating intense localelectromagneticfieldsthat can assist surfacereactions in several ways. Wedemonstratedthat the photodegradation of differentorganicpollutants can be controlled with unprecedentedspatial and time resolution and the reaction rate can be remarkablyenhanced.

The ongoingresearchisaddressed to the production of similarcatalysts over a large scale throughlow-coststrategies.

Metal NPs
can be exploitedasveryefficientphoton-thermalconverters to generate localizedheatat the micro- and nanoscale (optothermalconversion). Thiskeypropertyiscurrentlybeinginvestigated for a number of importantapplications in variousresearchfields, includingdrug delivery, cancerdiagnostics and therapy. Furtherimportantsectorsthat can benefit from plasmonicheating are micro- and nanofabrication and plasmon-assistedchemicalvapourdeposition. WeusedAuNPsas light harvesting centers to bringextremelylocalizedheatingintocolloidalparticles and colloidalassemblies, obtaining a selectivemodification of theirmorphology. Moreover, wedemonstratedhowplasmonicheating can be harnessed and convenientlyemployed to yield ‘‘hot’’ sites
for surfaceenhancedRamanspectroscopy (SERS) whichwerebased
on in situ generated metal oxides.

Smart materials, i.e. materialsthat can changetheirstructural and/or functionalproperties in response to externalstimuli, (light, pH,
electrical and magneticfields, mechanical stress, corrosion, etc.) are attractingevergrowinginterests in severalkeysectors of materials science. Adaptiveinterfaces, bioinspiredactuators, self-healingpolymercoatingsnanoparticles and tissues are only a few of the mostintensivelyinvestigatedsystems.

An interestingexampleisrepresented by pressure-sensitive adhesives, a class of materialsincludingacrylics, polyurethanes, polyesters, and silicones, are widelyused for a variety of applications in everyday life.In particular, uponmodification

with electricallyconductivefillers, suchas carbon or metals, they can be appliedasantistatic self-adhesivetapes for electromagnetic-shieldingpurposes in variouscontexts. Is t possible to makeconductivePSAs ‘‘smarter’’ and further

extendtheirapplicationrange? And if
so, how?

Wehavedemonstratedthat carbon-filledPSAs can be easilyadapted to work as
laser-writable and rewritableadhesivesubstrates. Thissystemisbased on cooperative interplaybetween the viscoelasticproperties of PSAs and enhancedthermalconductivityprovided by a thinoverlayer of gold. The information stored can be eitherpreserved or eraseddepending on surfacemodifications (e.g., by addingprotectingcoatings). In particular, the generation of self-expiringgraphicaltracks can have an impact on security, anti-forgery, labeling, quality control, and so on. From a fundamentalstandpoint, the interest for thesestudiesencompasses self-catalyticsystems and stimuli-responsive membranes.

More recently, we have successfully exploited oscillating chemical reactions to store temporary information in cellulose-based supports with precise control of self-erasing time and good spatial resolution.

Ultrasensitivevibrationalspectroscopytechniquesallow decisive breakthroughs in manydisciplines, includingchemistry, physics, materials and life sciences, becausethey can provideinsightful information about
intra- and interatomic bonds and physico-chemicalprocessesdynamics. Surface-enhancedRamanscattering (SERS) is
a leadingnondestructivetechniquethat can extend the sensitivity of Ramanspectroscopy to the level
of single molecule. However, for a number of importantapplications, suchas in situ Ramanmonitoring of chemicalreactions, plasmon-based SERS substrates can introduce strong perturbationsinto the systems under investigation. Thispreventsextraction of unbiased data and represents a stillunsolved major drawback.

We
are currentlyinvestigating alternative approaches to develop new materialsbased on core/shellmultifunctionalbeads and nanostructures. The ultimate goal of thisactivityis to advance in understanding the mechanisms and dynamics of technology-relevantprocesses under realworkingconditions, with a special focus on energy conversion and environmental remediation.

This part of the research activity recently led to the discovery and development of all-dielectric beads (T-rex) and related core/shell architectures which enabled to develop plasmon-free SERS, with exciting applications for environmental science and biodiagnostics.